1. Field of the Invention
The present invention relates to a portable communication terminal such as a foldable cellular phone having a function device (application device) such as a display unit and capable of implementing various functions.
2. Description of the Related Art
FIGS. 2A and 2B are views showing the appearance of a foldable cellular phone. FIG. 2A shows an opened state; and FIG. 2B shows a folded state. The cellular phone includes an upper enclosure 20 in which an LCD (liquid crystal display) panel, a camera, etc. are mounted, a lower enclosure 10 in which a transmission/reception circuit, a CPU, etc. are mounted, and a folding portion 30 for foldably coupling these enclosures.
The upper enclosure 20 includes, on its inner side, a main LCD panel 2 which can be seen when opened. The upper enclosure 20 also includes, on its outer side, an antenna 1, a high sensitivity mobile camera 3, a positioning mirror 4 serving as a standard of a display range of an image, an LED (light emitting diode) 5, a subsidiary LCD panel 6. The LED 5 displays e.g. calling information. The subsidiary LCD panel 6 displays telephone calling or mail reception, date, time, etc. The lower enclosure 10 includes a key operation portion 9.
In the foldable cellular phone as shown in FIG. 2, a wireless portion (transmission/reception circuit) for transmission/reception, a CPU for control execution, a memory such as a ROM and RAM are generally provided in the lower enclosure 10. The CPU controls the display unit such as the main LCD panel 2 and camera provided in the upper enclosure 20 (see: JP-A-2003-198676).
In such a foldable cellular phone equipped with a camera, between the upper enclosure 20 and the lower enclosure 10, signal wires between the camera and the CPU or memory are provided in addition to the signal wires between the display unit and CPU or memory. The cellular phone, therefore, presented a structural problem that the wire harness at the folding portion 30 is bulky.
Further, the image picked up by the camera is monitored on the display unit. For this purpose, the image must be updated at a high-speed rate (e.g. 15 frames/sec) to a certain degree. The camera has e.g. three and several thousands of pixels. The image is displayed in full color on the display screen of the display unit having a size of 176 dots (width)×220 dots (length). Thus, a large quantity of data is required for a camera image.
In a case where a game function is added to the foldable cellular phone, the CPU located in the lower enclosure 10 processes the data for the game function, and the display unit in the upper enclosure 20 displays the image as the processing result. A large quantity of data is also required for implementing the gate function.
In this way, in order to process a huge quantity of data required for a function device (application device) such as the camera and game, the huge quantity of high speed signals (clocks, image data) pass through the wire harness of the folding portion 30. This presented a problem of an increase in power consumption owing to the capacitive load of the wire harness.